US4389338A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacture of silver catalyst for production of ethylene oxide
Assignee: Nippon Shokubai Co Ltd
•
Filing: 1981-12-17
•
Granted: 1983-06-21
•
Expires: 2001-12-17
Abstract
Abstract In a method for the manufacture of a silver catalyst having silver deposited on a porous inorganic carrier in conjunction with at least one reaction accelerator selected from the group consisting of alkali metals and thallium to be used for the production of ethylene oxide, the improvement comprising the steps of depositing silver on the porous inorganic carrier in conjunction with at least one reaction accelerator selected from the group consisting of alkali metals and thallium thereby preparing an activated silver catalyst and subsequently subjecting said silver catalyst to a high-temperature treatment at a temperature in the range of 550° to 950° C. in an inert gaseous atmosphere having an oxygen concentration of not more than 3 volume percent in the final step.
Inventors
- 👤 Masashi Mitsuhata
- 👤 Shin-ichi Nagase
- 👤 Takahiko Nakai
- 👤 Toshihiko Kumazawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:55
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/66; C; C07; C07D; C07D301/00; C07D301/02; C07D301/03; C07D301/04; C07D301/08; C07D301/10; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
123 words
In a method for the manufacture of a silver catalyst having silver deposited on a porous inorganic carrier in conjunction with at least one reaction accelerator selected from the group consisting of alkali metals and thallium to be used for the production of ethyelene oxide, the improvement comprising the steps of depositing silver on the porous inorganic carrier in conjunction with at least one reaction accelerator selected from the group consisting of alkali metals and thallium thereby preparing an activated silver catalyst and subsequently subjecting said silver catalyst to a high-temperature treatment at a temperature in the range of 550° to 950° C. in an inert gaseous atmosphere having an oxygen concentration of not more than 3 volume percent in the final step.
Claim 2
Dependent Claim
123 words
In a method for the manufacture of a silver catalyst having silver deposited on a porous inorganic carrier in conjunction with at least one reaction accelerator selected from the group consisting of alkali metals and thallium to be used for the production of ethyelene oxide, the improvement comprising the steps of depositing silver on the porous inorganic carrier in conjunction with at least one reaction accelerator selected from the group consisting of alkali metals and thallium thereby preparing an activated silver catalyst and subsequently subjecting said silver catalyst to a high-temperature treatment at a temperature in the range of 550° to 950° C. in an inert gaseous atmosphere having an oxygen concentration of not more than 3 volume percent in the final step.
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein the oxygen concentration in the inert gas is not more than 1 volume percent.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein the oxygen concentration in the inert gas is not more than 0.1 volume percent.
Claim 5
Dependent Claim
28 words
A method according to claim 1, wherein the inert gas is at least one member selected from the group consisting of nitrogen, carbon dioxide, helium, argon, and neon.
Claim 6
Dependent Claim
25 words
A method according to claim 1, wherein the inert gas is at least one member selected from the group consisting of nitrogen, helium, and argon.
Claim 7
Dependent Claim
25 words
A method according to claim 1, wherein the high-temperature treatment is carried out at an elevated temperature in the range of 600° to 800° C.
Claim 8
Dependent Claim
18 words
A method according to claim 1, wherein the high-temperature treatment is carried out for at least three minutes.
Claim 9
Dependent Claim
24 words
A method according to claim 6, wherein the high-temperature treatment is carried out for a period in the range of 3 to 1440 minutes.
Claim 10
Dependent Claim
24 words
A method according to claim 6, wherein the high-temperature treatment is carried out for a period in the range of 20 to 900 minutes.
Claim 11
Dependent Claim
30 words
A method according to claim 1, wherein the amount of silver deposited in the catalyst is in the range of 5 to 25 weight percent based on the total catalyst.
Claim 12
Dependent Claim
26 words
A method according to claim 1, wherein the porous inorganic carrier has a specific surface area in the range of 0.1 to 5 m 2 /g.
Claim 13
Dependent Claim
26 words
A method according to claim 1, wherein the porous inorganic carrier has a specific surface area in the range of 0.2 to 3 m 2 /g.
Claim 14
Dependent Claim
26 words
A method according to claim 1, wherein the silver and the reaction accelerator are added and deposited on the porous inorganic carrier at the same time.
Claim 15
Dependent Claim
25 words
A method according to claim 1, wherein the reaction accelerator is added and deposited on the porous inorganic carrier before the deposition of the silver.
Claim 16
Dependent Claim
27 words
A method according to claim 1, wherein the reaction accelerator is added and deposited on the porous inorganic carrier after the deposition of the silver by precipitation.
Claim 17
Dependent Claim
14 words
A method according to claim 1, wherein the reaction accelerator is an alkali metal.
Claim 18
Dependent Claim
25 words
A method according to claim 16, wherein the alkali metal is at least one member selected from the group consisting of potassium, rubidium, and cesium.
Claim 19
Dependent Claim
12 words
A method according to claim 16, wherein the alkali metal is cesium.
Claim 20
Dependent Claim
30 words
A method according to claim 16, wherein the amount of the alkali metal deposited is in the range of 0.005 to 0.05 gram equivalent weight per kg of total catalyst.
Claim 21
Dependent Claim
30 words
A method according to claim 16, wherein the amount of the alkali metal deposited is in the range of 0.0085 to 0.03 gram equivalent weight per kg of total catalyst.
Claim 22
Dependent Claim
12 words
A method according to claim 1, wherein the reaction accelerator is thallium.
Claim 23
Dependent Claim
28 words
A method according to claim 21, wherein the amount of thallium deposited is in the range of 0.001 to 0.03 gram equivalent weight per kg of total catalyst.
Claim 24
Dependent Claim
28 words
A method according to claim 21, wherein the amount of thallium deposited is in the range of 0.002 to 0.02 gram equivalent weight per kg of total catalyst.
References Cited (Backward Citations)
US3962136A
Cited
US3962136B1
Cited
US4033903A
Cited
US4212772A
Cited
US4066575A
Cited
US4267073A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-20 | 1986-12-20 | 1987-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-20 | 1990-12-20 | 1991-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-20 | 1994-12-20 | 1995-06-21 | $7700.00 | Window Closed / Lapsed |